How to make 1 pdf from multiple

I found qpdf produced a much smaller output file than using pdfseparate and pdfunite to assemble pages into a 30-page output PDF, 970kB.When the job is finished, click Close, and close Adobe Acrobat Professional.Pdfunite is fine to merge entire PDFs.At that point you probably want a program with more options.Now, I clicked the Save button and provide a name for this profile settings, something like "Maximum quality".Click Save Export from the left panen Click Save Click the button that it's located between the left and right pane Click Specify Settings from the right panel.Click OK, click OK, click Save, provide a name for this Action, something like "Convert all to pdf at maximum quality then click Save.If you want, for example, pages 2-7 from file1.pdf and pages 1,3,4 from file2.pdf, you have to use pdfseparate to split the files into separate PDFs for each page to give to pdfunite.Adobe Acrobat Professional will start conversion, without unwanted prompts.Because it offers many more options, qpdf's command line is not as simple; the original request to merge file1 and file2 can be performed with qpdf -empty -pages file1.pdf file2.pdf - merged.If it prompt to save changes to untitled, click.